Pithecellobium circinale

Title

Pithecellobium circinale

Authors

Rupert C. Barneby

Scientific Name

Pithecellobium circinale (L.) Benth.

Description

3.Pithecellobium circinale (Linnaeus) Bentham, London J. Bot. 3: 201. 1844. Mimosa circinalis Linnaeus, Sp. Pl. 517. 1753. — "Habitat in America calidiore [= Haiti, fide Urban, 1920, l.c.. infra]." -Based on a drawing by Plumier in the Codex Boerhaavianus seen by Linnaeus in 1737 at Leiden in the herbarium of Boerhaave, later published by Johannes Burman, Pl. Amer. 1: 3, t. 5. 1755 (TL-2, 8069); the holotypus therefore the plate (copied from the original at Paris) at Leiden. The record by Linnaeus of having studied Burman’s copy of the Plumier drawing is illustrated incidentally in a reproduction of a Linnaean manuscript by Polhill & Steam, Taxon 25: 324. 1976 (Mimosa no. 4); the identification of the Plumier plate with P. circinale is documented by Urban, Repert. Spec. Nov. Regni Veg. Beih. 5: 36. 1920. — Inga circinalis (Linnaeus) Willdenow, Sp. Pl. 4: 1023. 1805.

Inga spinaefolia Desvaux, J. Bot. Appl. 3: 72. 1814. — "Habitat in America calidiore [doubtless Hispaniola]." — Holotypus, P (hb. Desvaux.)!. — Pithecolobium spini- folium (Desvaux) Bentjiam, J. Bot. 3: 200. 1844.— Equated with P. circinale by Bentham, 1875: 573.

Stiffly, diffusely branched, macrophyllidious, drought-deciduous, arborescent shrubs l-4(-5) m, armed at all or most nodes with a pair of conical or slenderly tapering spinescent stipules, puberulent throughout either with fine pallid, erect or forwardly incumbent hairs ±0.1-0.25 mm, the paucifoliolate lvs bicolored, the stiff, prominently venulose, sharply mucronate lfts darker green and often lustrous or glaucescent above, paler dull beneath, either glabrous or puberulent on both faces or glabrous above and dorsally puberulent over proximal anterior third of blade, the capitula of whitish fls arising either directly from coeval lf-axils or from variably condensed axillary branchlets toward the end of long-shoots, the erratically coiled fruits long persistent, often into anthesis of the second year. Stipules either widely ascending or subhorizontal, straight or obscurely recurved, sometimes all or mostly conic 1-2 mm but often, especially on long-shoots, all tapering and to 2-10 mm, persistent on old wood. Lf-formula i/1-3, but always in some longer pinnae the lfts 2-3-jug.; petioles (1.5—)2.5—15(—24) mm, openly grooved ventrally, not dilated upward; a cupular thick-rimmed nectary at tip of lf-stk either sessile or shortly stoutly stipitate, drum-shaped, or turbinate, 0.3-0.9 mm diam, in profile 0.25-0.8(-l.l) mm tall, a similar but smaller nectary at tip of each pinna-rachis; pinnae often of unequal length, the rachis of the longer one 6-34 mm, the one or the further interfoliolar segment (3-)4-12 mm; lft-pulvinules 0.5-1.1 x 0.35-0.7 mm, delicately wrinkled; lfts distally accrescent, in outline inequilaterally obovate or suborbicular from obliquely cuneate or postically shallow-cordate base, at apex broadly rounded or obscurely low-deltate and sharply mucronate by the stiffly excurrent midrib, the larger blades 10-33 x 7-30 mm, 1-1.5 times as long as wide, the terminal mucro (0.4-)0.7-2.5 mm; venation pinnate, the midrib subcentric or a little forwardly displaced, either straight or gently arched forward, giving rise on each side to 4—7 major and few random intercalary secondary nerves brochidodrome well within the plane, corneous-marginate, often shallowly undulate margin, and these in turn to a reticulum of sinuous connecting nervules, the whole venation of the mature blade yellowish and prominent on both faces. Peduncles solitary (on some short-shoots crowded, but subtended by a rudimentary lf-stk and always 1 per node), always slender, (7-) 10—35(—40) mm; fls 12-26 per capitulum, sessile, homomorphic, usually crowded on a clavate or subspherical receptacle 1.5—3 mm, rarely (e.g., Eyerdam 403, NY) shortly spicate on linear receptacle to 6-9 mm; bracts linear-spatulate or narrowly lanceolate 0.5-0.9 mm, persistent; perianth greenish white (brunnescent when dried), finely minutely puberulent overall; calyx campanulate 1.3— 2.1 x 0.8-1 mm, the triangular, often brownish teeth 0.1-0.35 mm; corolla subcylindric 4.6-6.6 mm, the erect ovate lobes 0.9-1.7 x 0.6-1 mm; androecium (16-)20-32-merous, (7-)8.5-14.5 mm, the stemonozone 0.7-0.9 mm, the tube 3.3-5 mm, lacking the basal callosities; ovary at anthesis usually glabrous or microscopically papillate becoming puberulent after fertilization, the permanently glabrous stipe 2.7-4 mm, 2-3 times as long as the narrowly oblong body; style a trifle longer than longest stamens, a little dilated at the stigma. Pods 1-2 per capitulum, in profile undulately linear and either evenly recurved through ±1-2 circles into an open ring or equivalently distorted, attenuate at base into a slender stipe, cuspidate at apex, when well fertilized 7-14 x 0.5-1 cm, 8-12- seeded, the inconspicuous sutures not raised to frame the valves and only shallowly strangulate between seeds, the leathery but flexible valves externally fuscous dull, minutely strigulose (finally glabrescent), internally reddish brown and fissured lengthwise, lacking septa; dehiscence through both sutures, the valves separating and independently twisted to display the seeds pendulous on a spongy red arilliform funicle; seeds compressed-lentiform, in broad profile either nearly round or obscurely obtusangulate ±4-6 x 3.5-5.5 mm, the hard testa lustrous black, either smooth or minutely rugulose, the pleurogram at middle of seed-face ±2-4 x 2-3 mm.

In thickets on the coast and on interior plains and hills below 150 m, on Cabritos I. in Lago Enriquillo at -30 m, locally common in E Cuba (Guantánamo and vicinity) and W and SW Hispaniola, in all departments of Haiti and in prov. Independencia, Barahona, Azua, and Peravia of Dominican Republic. — Map 2. — Fl. IX-IV(-VIII).

Pithecellobium circinale has the leaf-formula of the two preceding, distantly allopatric species, but differs by leaflets tipped with a spinulose excurrent midrib. Sympatric P. dulce and P. unguis-cati have exactly 4 leaflets in all leaves and are readily separable by this character. The fruit is essentially that of P. unguis-cati except on the average more slender, with smaller seeds.